Add OzoneGLImpl interface.

ui/gl/init/gl_initializer_ozone.cc

Index: ui/gl/init/gl_initializer_ozone.cc
diff --git a/ui/gl/init/gl_initializer_ozone.cc b/ui/gl/init/gl_initializer_ozone.cc
index fe43ed869e1f4d9bc51f30ef21cabc3f4b39c02a..7787be82825ef598f48c38b786495924289da65e 100644
--- a/ui/gl/init/gl_initializer_ozone.cc
+++ b/ui/gl/init/gl_initializer_ozone.cc
@@ -11,6 +11,7 @@
 #include "ui/gl/gl_implementation_osmesa.h"
 #include "ui/gl/gl_osmesa_api_implementation.h"
 #include "ui/gl/gl_surface_egl.h"
+#include "ui/gl/init/ozone_util.h"
 #include "ui/ozone/public/ozone_platform.h"
 #include "ui/ozone/public/surface_factory_ozone.h"
 
@@ -19,10 +20,6 @@ namespace init {
 
 namespace {
 
-ui::SurfaceFactoryOzone* GetSurfaceFactory() {
-  return ui::OzonePlatform::GetInstance()->GetSurfaceFactoryOzone();
-}
-
 bool InitializeStaticEGLInternal() {
   if (!GetSurfaceFactory()->LoadEGLGLES2Bindings())
     return false;
@@ -37,6 +34,9 @@ bool InitializeStaticEGLInternal() {
 }  // namespace
 
 bool InitializeGLOneOffPlatform() {
+  if (HasGLOzone())
+    return GetGLOzone()->InitializeGLOneOffPlatform();
+
   switch (GetGLImplementation()) {
     case kGLImplementationEGLGLES2:
       if (!GLSurfaceEGL::InitializeOneOff(
@@ -58,7 +58,11 @@ bool InitializeStaticGLBindings(GLImplementation implementation) {
   // unit tests have initialized with kGLImplementationMock, we don't want to
   // later switch to another GL implementation.
   DCHECK_EQ(kGLImplementationNone, GetGLImplementation());
-  ui::OzonePlatform::InitializeForGPU();

[piman, 2016/08/31 20:05:09]

nit: because this moves to >1 location, is there a way to add a DCHECK somewhere
to make sure we didn't miss any?

[kylechar, 2016/09/01 13:57:21]

I can add an explicit DCHECK(OzonePlatform::GetInstance()) at the start of
InitializeGLOneOffPlatform() and InitializeStaticGLBindings() for sure.

Realistically it doesn't make much difference because
OzonePlatform::GetInstance() has it's own DCHECK, so that will be what fails. It
would also be what fails now on the first HasGLOzone() call in both of those
methods.

Another option is to move OzonePlatform::InitializeForGPU() to gpu_main.cc. It's
conceptually much nicer for Chrome because initializing OzonePlatform as part of
GL initialization seems flawed. What if we don't want to initialize GL (eg.
Vulkan) then OzonePlatform doesn't get initialized. The big problem with this is
there are ~10 unit tests that also need to initialize OzonePlatform in their
main or test fixture.

[piman, 2016/09/01 17:43:04]

Ok, if it's redundant, then nbd.
It may make sense to have it both in gpu_main.cc and GLSurfaceTestSupport,
because the latter is intended to initialize all the platform requirements for
GPU, indeed to avoid having to maintain 10ish test suites. Up to you.

+
+  if (HasGLOzone(implementation)) {
+    return GetGLOzone(implementation)
+        ->InitializeStaticGLBindings(implementation);
+  }
 
   switch (implementation) {
     case kGLImplementationOSMesaGL:
@@ -77,12 +81,22 @@ bool InitializeStaticGLBindings(GLImplementation implementation) {
 }
 
 void InitializeDebugGLBindings() {
+  if (HasGLOzone()) {
+    GetGLOzone()->InitializeDebugGLBindings();
+    return;
+  }
+
   InitializeDebugGLBindingsEGL();
   InitializeDebugGLBindingsGL();
   InitializeDebugGLBindingsOSMESA();
 }
 
 void ClearGLBindingsPlatform() {
+  if (HasGLOzone()) {
+    GetGLOzone()->ClearGLBindings();
+    return;
+  }
+
   ClearGLBindingsEGL();
   ClearGLBindingsGL();
   ClearGLBindingsOSMESA();